package com.itstyle.seckill.distributedlock.zookeeper;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.framework.recipes.locks.InterProcessMutex;
import org.apache.curator.retry.ExponentialBackoffRetry;
/**
 * 基于curator的zookeeper分布式锁
 * 这里我们开启5个线程，每个线程获取锁的最大等待时间为5秒，为了模拟具体业务场景，方法中设置4秒等待时间。
 * 开始执行main方法，通过ZooInspector监控/curator/lock下的节点如下图：
 */
public class CuratorUtil {
    private static String address = "192.168.1.180:2181";
	
    public static void main(String[] args) {
		//1、重试策略：初试时间为1s 重试3次
		RetryPolicy retryPolicy = new ExponentialBackoffRetry(1000, 3); 
		//2、通过工厂创建连接
		CuratorFramework client = CuratorFrameworkFactory.newClient(address, retryPolicy);
        //3、开启连接
        client.start();
        //4 分布式锁
        final InterProcessMutex mutex = new InterProcessMutex(client, "/curator/lock"); 
        //读写锁
        //InterProcessReadWriteLock readWriteLock = new InterProcessReadWriteLock(client, "/readwriter");
        
        ExecutorService fixedThreadPool = Executors.newFixedThreadPool(5);
        
        for (int i = 0; i < 5; i++) {
            fixedThreadPool.submit(new Runnable() {
                @Override
                public void run() {
                	boolean flag = false;
                	try {
                		//尝试获取锁，最多等待5秒
                		flag = mutex.acquire(5, TimeUnit.SECONDS);
                		Thread currentThread = Thread.currentThread();
                		if(flag){
                			System.out.println("线程"+currentThread.getId()+"获取锁成功");
                		}else{
                			System.out.println("线程"+currentThread.getId()+"获取锁失败");
                		}
                		//模拟业务逻辑，延时4秒
                		Thread.sleep(4000);
					} catch (Exception e) {
						e.printStackTrace();
					} finally{
						if(flag){
							try {
								mutex.release();
							} catch (Exception e) {
								e.printStackTrace();
							}
						}
					}
                }
            });
        }
	}
}
